Interpretive Summary: Gossypium hirsutum L. accounts for more than 90% of the commercial cotton fiber production in the United States, but typically has inferior fiber attributes relative to modern G. barbadense L. cultivars. Efforts to improve G. hirsutum fiber quality through introgression from G. barbadense have been slowed by a reduction in fertility and vigor in advanced generations of G. hirsutum X G. barbadense populations, thus slowing the transfer of superior fiber traits from G. barbadense to Upland cotton breeding programs. To overcome this limitation, a population of recombinant inbred lines was developed by crossing NM24016, an elite G. hirsutum inbred line with considerable but stabilized introgression from diverse G. barbadense lines, with TM-1, the genetic standard of G. hirsutum. The resultant TM-1/NM24016 population of 95 recombinant inbred lines had exceptional variation for fiber traits and some of which exceeded the superior parent. The registration of this novel mapping resource will increase its accessibility to the global cotton breeding and genetics community, which will better facilitate the genetic improvement of fiber quality in Upland cotton.

Technical Abstract:
The TM-1/NM24016 cotton (Gossypium hirsutum L.) mapping population consists of 95 F5:9 recombinant inbred lines. This cotton mapping population was constructed from a cross between inbred lines TM-1, the genetic standard for G. hirsutum, and NM24016, an advanced selection with stable expression of introgressed traits from G. barbadense L. and G. hirsutum. In 2007, the population was jointly released by the Plant Physiology and Genetics Research Unit, USDA-ARS, Maricopa, AZ and New Mexico State Agricultural Experiment Station, Las Cruces, NM. The primary goal was to construct a mapping population segregating for attributes introgressed from G. barbadense into a predominant G. hirsutum germplasm background. The TM-1/NM24016 population was genotyped with 392 simple sequence repeat markers. Tremendous phenotypic diversity among individuals has been observed for fiber and agronomic traits, with positive transgressive variation for the majority of fiber traits. The registration of this recombinant inbred mapping population provides geneticists and breeders with an opportunity to explore the genetic basis of transgressive variation in cotton and exploit potentially novel allelic combinations for the genetic improvement of fiber quality and other traits in G. hirsutum.